Re: New alvarezsaurid

["John R. Hutchinson" <jrhutch@socrates.berkeley.edu>]

At 6:21 AM -0500 3/19/98, Jonathon Woolf wrote:

>Yet another new dino-find in the news: This week's issue of NATURE
>contains a description of a new alvarezsaurid from Mongolia.  The name
>given is _Suvuuia deserti_.

_Shuuvuia deserti_ (shoo-voo-yah). It's two skulls, plus some material
previously referred to _Mononykus_. I saw the material at the AMNH this
winter and man, is it amazing! Not to mention the postcrania; nice pelvis
and hindlimbs there. I doubt even the best photos can do the specimens
justice; the 3D preservation is astounding. Several ornithologists have
seen the skulls and been convinced of their avian affinity; the things are
more like neornithines than _Archaeopteryx_ is. After seeing the specimens
firsthand, I agree with some that think alvarezsaurids may end up /further/
up the avian tree.

However, we need good basal alvarezsaurid material for polarity. A
_Patagonykus_ or _Alvarezsaurus_ skull would be nice. Ghost taxon
contraints place the earliest alvarezsaurids in the Early Cretaceous, which
implies that we're missing a big chunk of alvarezsaurid history. I'd be
very surprised if their current phylogenetic placement varied more than one
node up or down the tree; I think it's pretty close as is, judging from the
available data. The forelimbs really confuse matters, though. I wonder what
the forelimbs of an Albian alvarezsaurid would look like.

Neat stuff! (And more alvarezsaurids to come!)

                       --John R. Hutchinson